The effect of free convection on heat transfer and on the flow field about a rotating cone is studied. A similar solution for the laminar boundary-layer equations is found to exist when the cone surface temperature varies linearly with distance from the cone apex. The transformed boundary-layer equations contain the important parameter Gr/Re2 . This parameter determines the relative importance of the free convection motions on forced convection. Numerical solutions of the transformed equations for aiding flows have been carried out for Prandtl number 0.7 and different values of Gr/Re2 . Results are reported for the heat transfer, shear stress, shaft moment, and velocity and temperature fields. Criteria are given for subdividing the regimes of flow as purely free, purely forced, and combined flow. Preliminary experimental heat-transfer results are reported which indicate the trends predicted by theory.